Vehicles such as automobiles are equipped with a catalyst converter for removing harmful substances such as carbon monoxide, hydrocarbons, and nitrogen oxides contained in exhaust gas. An example of the catalyst converter is a converter including a tubular catalyst carrier, a tubular metal casing for housing the tubular catalyst carrier, and a mat-shaped holding material formed of inorganic fibers arranged between the catalyst carrier and the casing.
For such catalyst converter, there have hitherto been attempts to improve holding force of the holding material with a view to stable holding of the catalyst carrier in the metal casing (see, for example, Patent Literature 1).